If there’s deficiency of Vitamin D in a
child, we call this rickets.
But, interesting enough, you take a look at
the child and there’s bone.
So, how is it possible that with Vitamin D
deficiency in a child that there’s bone,
but there’s hypocalcemia or there’s Vitamin
Well, understand the following.
With Vitamin D deficiency, which renders a
child hypocalcemic, at some point in time
may trigger PTH to be released.
The parathyroid hormone that’s being released
in a child may then-then-then turn to the
bone or more importantly, may turn to the
It reabsorbs the calcium, but the problem
is it’s not going to reabsorb phosphate,
So, you might have excess calcium, but you
might not have the phosphate to properly form
what kind of bone?
So, if you don’t have mineralized bone,
you don’t have strong bone, but you can
have weak bone and this weak bone then softens.
You notice here in this child that there is
a bowing of the legs because the weight that
the child is placing upon the bone is not
able to properly support the child.
So, therefore, there will be bowing or bending.
Not only that, the bowing of the legs will
take place, but in addition, if you see what’s
here, it’s called Looser’s zone.
What that represents is the following.
You probably have seen rickets quite a bit.
You’ve heard of frontal bossing, you’ve
heard of rachitic rosary, you’ve heard of
So, how is it possible that you don’t have
Vitamin D, but then you also have frontal
bossing, rachitic rosary or radial overgrowth?
What’s happening is the fact that, remember,
once again, you might have insufficient amounts
of phosphate, in fact, you do.
You don’t have enough phosphate, so you’re
not mineralizing the bone.
If you’re not mineralizing the bone then
what you expect here and what you’re seeing
here on the X-ray would be the epiphyseal
plate and this epiphyseal plate is not being
You call this a Looser’s zone, fracture-like
Enlarged liver and spleen, profuse sweating,
generalized tenderness, listlessness and insomnia
are all parts of your clinical manifestations
Bottom line, as the first stanza says, defective
mineralization due to lack of phosphate availability.